1. Field of the Invention
The present invention relates to a data backup method for a flash memory module and a solid state drive.
2. Description of Related Art
Providing high capacity and long service life non-volatile memory in consumer electronics produces is increasingly important nowadays. With the rapid advancement of the flash memory technology, high capacity and long service life non-volatile memory device constructed by flash memory has become the main stream.
FIG. 1 illustrates a conventional flash memory module 100. Referring to FIG. 1, the flash memory module 100 consists of a plurality of flash memory units 111-13N. The flash memory units 111-13N are grouped into a plurality of channels CH1-CH3. The channel CH1 includes the flash memory units 111-11N, the channel CH2 includes the flash memory units 121-12N, and the channel CH3 includes the flash memory units 131-13N.
In order to speed up data accessing, a single piece of data is conventionally divided into multiple pieces of data that are accessed simultaneously through the respective channels CH1-CH3. As such, the data accessing speed can be several times higher than the speed of accessing through the single flash memory unit. However, this way of accessing also causes the single piece of data to be dispersedly saved in different flash memory units 111-13N. In other words, if a few of the flash memory units 111-13N is damaged, the piece of data is likely to be lost.
Accordingly, data backup of the flash memory module 100 is of particular importance. In addition, in order to prolong the overall life span, a wear leveling technology has been developed in the flash memory module 100. The wear leveling technology can result in an even distribution of erasures of the flash memory units by exchanging the data of those flash memories whose erasures differ greatly. While this technology can extend the overall service life, it can cause the data in the flash memory to be disorder and discontinuous. Therefore, once a few of the flash memory units are damaged, data recovery can be more difficult. Data backup in the flash memory module 100 can also be done simply by using a flash memory module having the same capacity as the flash memory module 100.